Javascript  |  56行  |  2.1 KB

// Copyright 2013 the V8 project authors. All rights reserved.
// Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1.  Redistributions of source code must retain the above copyright
//     notice, this list of conditions and the following disclaimer.
// 2.  Redistributions in binary form must reproduce the above copyright
//     notice, this list of conditions and the following disclaimer in the
//     documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
// ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

description(
"This tests that a structure clobber in a basic block that does not touch a live variable causes that variable's structure to be correctly clobbered."
);

var clobberedObject;

function bar() {
    if (!clobberedObject)
        return;
    delete clobberedObject.f;
    clobberedObject.g = 42;
}

function foo(p, o_) {
    var o = o_.f; // Force this block to have a SetLocal.
    var x = o.f;
    if (p)
        bar();
    return x + o.f;
}

var expected = 2;

for (var i = 0; i < 200; ++i) {
    var object = {f:1};
    var predicate = true;
    if (i >= 150) {
        clobberedObject = object;
        expected = 0/0; // "NaN"
    }
    shouldBe("foo(predicate, {f:object})", "" + expected);
}